body {
  background: #F2F4F7;
}
* {
  margin: 0;
  padding: 0;
}
ul {
  list-style: none;
}
h1,
h2,
h3,
h4,
h5,
h6 {
  display: inline-block;
  margin-top: 0;
  margin-bottom: 0;
}
a {
  color: #666;
  text-decoration: none;
  font-size: 16px;
}
a:hover {
  text-decoration: none;
}
a:focus {
  text-decoration: none;
}
.center_main {
  width: 1100px;
  margin: 0 auto;
}
.header {
  position: relative;
  display: flex;
  align-items: center;
  position: fixed;
  z-index: 999;
  top: 0;
  width: 100%;
  height: 60px;
  background-color: #fff;
  box-shadow: 0 0px 5px rgba(0, 0, 0, 0.25);
  background: -webkit-linear-gradient(-45deg, rgba(28, 105, 243), rgba(80, 149, 243));
}
.header .logo {
  width: 160px;
  height: 100%;
  background-color: #ccc;
  margin-left: 40px;
}
.header .logo h1 {
  display: inline-block;
}
.header .logo h1 a {
  font-size: 0;
}
.header .logo h1 a:hover {
  cursor: pointer;
}
.header .search {
  border-radius: 20px;
  overflow: hidden;
  flex: 1;
  align-self: center;
  width: 200px;
  margin-left: 300px;
  margin-right: 300px;
}
.header .search input {
  padding-left: 20px;
}
.header .search button {
  font-weight: 600;
}
.header .self-info {
  cursor: pointer;
  margin-right: 100px;
}
.header .self-info .username a {
  font-size: 20px;
  color: white;
}
.header .self-info .username span {
  color: white;
  font-size: 15px;
}
.header .account-operate {
  position: absolute;
  display: flex;
  border-radius: 10px 10px 0 0;
  width: 130px;
  height: 130px;
  top: 60px;
  right: 65px;
  background: -webkit-linear-gradient(-45deg, rgba(28, 105, 243), rgba(80, 149, 243));
}
.header .account-operate ul {
  margin-top: 10px;
  display: flex;
  flex-direction: column;
  flex: 1;
}
.header .account-operate ul li {
  flex: 1;
  height: 100%;
  line-height: 55px;
  text-align: center;
}
.header .account-operate ul li a {
  color: #fff;
  font-size: 20px;
}
.header .account-operate ul li:hover {
  background-color: #87bbeb;
}
